Yampa River Basin Research Final Synthesis Report

Home Browse Search

• Flow augmentation alternatives: Primary flow management options under consideration are no action and augmentation of low stream flows during August- October from existing or new storage, interruptible supply contracts with irrigators, or some combination of options. Are these acceptable alternatives? Are there other scenarios that should be considered? There is no clear consensus on this issue. The USFWS estimates that 3,000 AF of water would satisfy augmentation needs of fishes from July through October in 16 of the 17 CRDSS years at the Maybell gage under 2025 demand conditions (see Appendix B). Above the Maybell diversion this volume would adequately augment flows for fish under 2045 demand conditions. The USFWS believes that its existing lease with Colorado for up to 3,300 AF of water from Steamboat Lake should be extended. This amount has been decreed for instream flows. However, there must be some practicable means of protecting this water from Steamboat Lake downstream to the Maybell gage (see River administration and depletion accounting below). There are other options to consider in addition to the Steamboat Lake lease. Leasing water from power companies is one such option. Power companies hold water rights or contracts for water stored in Steamboat Lake, Stagecoach and Elkhead Reservoirs and released as needed to cool their thermo - electric generating plants. Because this water may be needed only during extreme conditions, it may be available to augment flows for fish during less extreme low -flow periods. Another option, whose feasibility has yet to be fully investigated, is interruptible supply contracts or dry year options. Municipalities have adopted dry year options as an alternative to buying agricultural water rights and permanently retiring them. Because municipal water demands vary from year to year, municipalities may experience surpluses under certain conditions and shortages under other conditions. Interruptible supply contracts address this contingency by alternating use of an existing water supply between a farm and a municipality who, in effect, share a water right. Irrigators retain ownership or control of the underlying water right and continue to use the water most of the time, while the municipality buys an option from the irrigators to interrupt that use and take delivery during the infrequent occasions when its other supplies are exceptionally low or its demands are exceptionally high. Both municipal and agricultural sectors benefit from this arrangement, since market forces otherwise might drive land out of agriculture. Under this option, a certain number of water deliveries would be specified over a set number of years and a premium would be paid over of the cost of the water for the extra control the municipality enjoys. Leasing water from agricultural or more structured dry year options could also be applied to augment infrequent shortages in low stream flows for fish without permanently retiring irrigated lands. However, dry year options are constrained in the lower Yampa by several factors: Depletions by agriculture decline after July; therefore, there is less water available to lease per acre late in the irrigation season, which would require more acreage to be taken out of irrigation to meet any specific flow target. The application of dry year options in July would yield relatively more water per acre; however, hydrologic analyses indicate that augmentation rarely would be needed in July. Moreover, during dry years there may be insufficient water to satisfy junior irrigation demands; therefore, dry year options with irrigators who have junior water rights would produce little instream benefit in dry years. Constructing new storage ( Elkhead enlargement) in part to augment flows for fish had been considered in the past. Opponents of new storage point to its high financial cost and its potential impact on spring peak flows. They believe the Steamboat Lake lease is sufficient to meet the flow needs of fishes well into the foreseeable future, and the RIP should apply its finite financial resources to this and similar RIPRAP elements that provide more cost - effective benefits for endangered fishes. 20